Deir Al-Balah: New Israeli strikes on Rafah have killed at least 16 Palestinians, first responders said Tuesday, as residents reported an escalation of fighting in the southern Gaza city once seen as the territory's last refuge.

An Israeli incursion launched in early May has caused nearly 1 million to flee from Rafah, most of whom had already been displaced in the war between Israel and Hamas. They now seek refuge in squalid tent camps and other war-ravaged areas.

The United States and other close allies of Israel have warned against a full-fledged offensive in the city, with the Biden administration saying that would cross a red line and refusing to provide offensive arms for such an undertaking. On Friday, the International Court of Justice called on Israel to halt its Rafah offensive, an order it has no power to enforce.

Prime Minister Benjamin Netanyahu has vowed to press ahead, saying Israeli forces must enter Rafah to dismantle Hamas and return hostages taken in the Oct. 7 attack that triggered the war.

The latest strikes occurred in the same area where Israel targeted what it said was a Hamas compound on Sunday night. That strike ignited a fire in a camp for displaced Palestinians and killed at least 45 people, according to local health officials, sparking worldwide outrage.

Netanyahu called it a “tragic mishap" and the military said it was investigating.

The new strikes overnight killed a total of 16 people in the Tel al-Sultan neighborhood in northwest Rafah, according to the Palestinian Civil Defense and the Palestinian Red Crescent.

Israel says it is carrying out limited operations in eastern Rafah along the Gaza-Egypt border. But residents reported heavy bombardment overnight in western parts of Rafah as well.

“It was a night of horror,” said Abdel-Rahman Abu Ismail, a Palestinian from Gaza City who has been sheltering in Tel al-Sultan since December. He said he heard “constant sounds” of explosions overnight and into Tuesday, with fighter jets and drones flying over the area.

He said it reminded him of the Israeli invasion of his neighborhood of Shijaiyah in Gaza City, where Israel launched a heavy bombing campaign before sending in ground forces in late 2023. “We saw this before,” he said.

Sayed al-Masri, a Rafah resident, said many families have been forced to flee their homes and shelters, with most heading for the crowded Muwasi area, where giant tent camps have been set up on a barren coastline, or to Khan Younis, a southern city that suffered heavy damage during months of fighting.

“The situation is worsening” in Rafah, al-Masri said.

Gaza’s Health Ministry said two medical facilities in Tel al-Sultan are out of service because of intense bombing nearby. Medical Aid for Palestinians, a charity operating throughout the territory, said the Tel al-Sultan medical center and the Indonesian Field Hospital were under lockdown, with medics, patients and displaced people trapped inside.

Most of Gaza's hospitals are no longer functioning. The Kuwait Hospital in Rafah shut down Monday after a strike near its entrance killed two health workers.

A spokesperson for the World Health Organization said the casualties from Sunday’s strike and fire “absolutely overwhelmed” field hospitals in the area, which were already running short on supplies to treat severe burns.

“That requires intensive care, that requires electricity, that requires high-level medical services,” Dr. Margaret Harris told reporters in Geneva. “Increasingly, we are struggling to even have the high-level skilled doctors and nurses because they’ve been displaced.”

The war began when Hamas and other militants burst into southern Israel in a surprise attack on Oct. 7, killing some 1,200 civilians and abducting around 250. More than 100 were released during a weeklong cease-fire in November in exchange for Palestinians imprisoned by Israel.

Israel responded to the attack with a massive air, land and sea offensive that has killed at least 36,096 Palestinians, according to Gaza's Health Ministry, which does not distinguish between fighters and civilians in its count. Around 80% of Gaza's population of 2.3 million has been displaced and United Nations officials say parts of the territory are experiencing famine.

The fighting in Rafah has made it nearly impossible for humanitarian groups to import and distribute aid to southern Gaza.

The Israeli military says it has allowed hundreds of trucks to enter through the nearby Kerem Shalom crossing since the start of its operation, but aid groups say it’s extremely difficult to access that aid on the Gaza side because of the fighting.

The U.N. says it has only been able to collect aid from around 170 trucks over the past three weeks via Kerem Shalom. Smaller amounts of aid are entering through two crossings in the north and by sea through a U.S.-built floating pier, but it’s nowhere near the 600 trucks a day that aid groups say are needed.